Experimental Analysis of Acoustic Performance of Porous Ducts using a Small- scale Shock tube

Abstract

A Shock tube is a device often used to recreate the shock phenomena by several methods. The present work is a preliminary study to analyse the efficiency of baffles in suppressing the noise generated from the shock associated jet ejected from the duct exit. The experiment was performed at a shock Mach number of 1.27 using a diaphragm based, small scale, open ended shock tube. Parametric study conducted by varying the baffle dimensions such as outer diameter, hole diameter and porosity reveals that the baffles with hole diameter less than half of the baffle diameter and with a greater porosity is a cost effective and efficient noise suppressor for shock associated jets.